Previous posts (e.g., here and here) discussed the series of patent infringement suits brought by GreenShift and its New York subsidiary, GS Cleantech (GS), against a host of ethanol producers across the midwestern United States.

The litigation currently consists of 11 actions consolidated in the Southern District of Indiana in which GreenShift has accused the defendants of infringing U.S. Patent Nos. 7,601,858 (’858 Patent), 8,008,516 (’516 Patent) and 8,283,484 (’484 Patent), entitled “Method of processing ethanol byproducts and related subsystems” and U.S. Patent No. 8,008,517 (’517 Patent), entitled “Method of recovering oil from thin stillage.” The latter three patents were recently added to the case.

The patents relate to methods of recovering oil from byproducts of ethanol production using the process of dry milling, which creates a waste stream comprised of byproducts called whole stillage. The patented methods include mechanically separating the whole stillage into distillers wet grains and thin stillage and then running the thin stillage into an evaporator to form a concentrated byproduct, or syrup. The syrup is fed through a second centrifuge, which separates usable corn oil from the syrup.

Following a mixed claim construction ruling, a number of defendants filed motions for summary judgment of non-infringment of the ’858, ’516 and/or ’517 Patents, and GS filed a motion for summary judgment of infringement of the ’858 and ’516 Patents.

In a recent decision the court revisited its interpretations of a few claim terms and, based on the new constructions, denied the SJ motions all around without prejudice. The key term the court focused on was “substantially free of oil” / “substantially oil free.”

The defendants argued that all of the patent claims require the concentrate or syrup after the oil recovery step to be substantially free of oil. The court disagreed and held that none of the claims of the ’858 Patent have this requirement and only claim 7 of the ’516 Patent and claim 8 of the ’484 Patent require that the post-oil recovery step syrup stream be substantially oil free.

Another issue in interpreting the “substantially oil free” term was whether it should be defined as a comparison between the oil concentration in the incoming thin stillage stream and the outgoing remaining-concentrate stream. The defendants also contended that the term should mean the post-oil recovery thin stillage stream contains 5% or less of the oil in the incoming stream.

The court agreed with the comparison but declined to impose a quantitative requirement for the percentage of oil. Accordingly, the term “substantially oil free” was interpreted according to the ordinary meaning of largely and mostly oil free but is measured by a comparison of the oil concentration in the incoming thin stillage and the oil concentration in the resulting syrup:

[T]he Court concludes that the “substantially oil free” limitation in claim 7 of the ’516 Patent and claim 8 of the ’484 Patent means the syrup exiting the centrifuge is substantially oil free compared to the incoming thin stillage, where substantially has its ordinary meaning of largely or mostly.

The court went on to dismiss all of the pending summary judgment motions without prejudice and with leave to re-file. In view of the new claim construction and the recent addition of three patents to the litigation, the court decided the parties would need more time to develop their arguments on infringement:

[T]he Court recognizes that the decisions in this Order will have an impact on the parties’ positions with respect to infringement. In addition, as discussed in the introduction, since the date the parties filed their summary judgment motions the Court has allowed CleanTech to amend its complaints against each Defendant such that nearly all patents in the ’858 patent family are asserted against each of them. For both of these reasons, the currently-briefed summary judgment motions likely do not address all the arguments the parties wish to raise with respect to CleanTech’s allegations of infringement and, to resolve the infringement issues fairly, the Court will require the parties to address the allegedly infringing processes under the new claim construction.